128 EXPLANATION OF TERMS 



Spur: a short, stiff, generally blunt process and usually not articulated at its 

 base : in the plural refers to paired spiniform processes at or near the end 

 of tibiae. 



Spur formula: a numerical expression of their arrangement; as 2-3-4; 2 

 spurs on fore tibia, 3 on middle, and 4 on posterior ; in Trichoptera. 



Spurius: false: applied to aborted anterior legs in some diurnal Lepidoptera. 



Spurious cell: in Diptera (Pack.), = 3d anal (Comst.). 



Spurious veins: certain folds or thickenings in the wing surface which re- 

 semble a vein so nearly as to be readily mistaken and sufficiently constant 

 to be useful in classification. 



Squama: in Odonata, the sclerite that bears the palpus of both maxilla and 

 labium: the scale-like first abdominal segment of some ants: a scale-like 

 appendage covering the base of primaries in Lepidoptera, and so = pata- 

 gium ; q. v. : a small scale above the halteres in Diptera: in this order 

 Packard uses squama for the lobed scale and restricts alula to the lobe- 

 like appendage : Osten-Sacken uses squama for the posterior scale alone 

 and antisquama for the anterior. 



Squames: the flattened, fimbriated or spine-like marginal processes of the 

 pygidium in Diaspina;, other than the lobes and true spines : = " plates," 

 of Comst. ; or " scaly hairs " of Maskell. 



Squamiform: having a scale-like form. 



Squamose-ous: scaly or covered with scales. 



Squamula: a small corneous scale covering the base of primaries in some 

 insects : = tegula ; q. v. : in Diptera, = alula. 



Squarrous: scurfy: clothed with rough scales differing in direction, standing 

 upright, or not parallel to the surface. 



Stadium -ia: the interval between the molts of larvae: = instar; q. v. : any 

 one period in the development of an insect. 



Stage: refers to the period of development; e. g., larval, pupal, etc. 



Stalked bodies: = gyri cerebrales ; q. v. 



Stellate: star-shaped; with four or five radiating lines. 



Stelocyttares: social wasps in which the comb layers of the nest are sup- 

 ported by pillars and not connected with the envelope : see poecilocyttares 

 and phragmocyttares. 



Stemapoda: the modified filamentous anal legs of Centra and other Noto- 

 dontid larvae. 



Stemmata: simple eyes or ocelli; q. v. 



Stem-mother: in plant lice, that form hatching from the winter egg, which 

 starts a series of agamic summer generations. 



Stenocephalous: with a narrow, elongate head. 



Stenorhynchan: narrow beaked or snouted. 



Stenothorax: a supposed ring between pro- and mesothorax. 



Stercoral: relating or pertaining to excrement. 



Sterile: not capable of reproducing its kind. 



Sternal orifice: in Perlids ; a peculiar slit on each side of the sternum, 

 extending inward and ending blindly : f urcal orifice. 



Sternal spatula: = breast-bone ; q. v. 



